System of motor control.



' PATENTED APR. 3, 1906.

A. MAGNUSON. SYSTEM OF MOTOR CONTROL.

APPLICATION FILED NOV. 16, 1905.

WlTNESSES:

SE SEY.

Specification of Letters Patent.

lipplicetion filed November 16, 1905. Serial No. 287,555.

Patented April 3,

10 m whom it may; concern.-

Be it known that l, AXEL MAoNUsoN, a citizen of the United States, ends. resident of New York city, in the county of New York and State of New York, have invented certain new and useful Improvements in Systems of Motor Control, of which the following is a specification.

My invent-ion relates to a system of motor 10 control; and it consists of a novel arrangement of various apparatus and circuits Whereby an electric motor may he stnrter'l, stopped, and otherwise controlled at will.

Although my system is applicable to other i 5 types of elec" ic inc-tors, it may he used to gre s t edventege in conjunction with such Inotoi's as operated. by alternating currents. w l have made application for Letters Petout, Serial No. 2e1,592, filed January 18,

1905, for 2i system of motor control which einbodies the broad idea of the present invention, cndthepresent invention is of certain improvements and developments of the invention dsclosed in said prior application.

The drawing shows an electric motor in side elevation, together with certain connected apparatus and electrical circuits.

l0 designates on electric motor, 11 its or- 0 mature, and 12 its shaft. 13 and 14- erc the brushes of this motor, which bear upon its commutator 15. 16 and 17 are the terminals of a shunt fieldovinding for this motor. 20 is a generator directly connected to ino- 35. tor-shaft 12. 21 is shunt field-wind g for this generator, and 22 and 232m; terminals for the shunt field-winding.

Zea-rid 25 designate brushes bearing upon the commutator of generator 20., and 26 and no 27 are conductors or leads connected to the brushes 2% and 25, respectively.

3t, and 31 designate the mains from a suitable source of current-supply. These pass through main line switch 32, fuses 33, end to certain other parts or" the apparatus, which will he pointed out fully hereinafter. i0 designates a manually-operated circuitcloser which comprises ssWitch-arn'i 41, pivoted st 42 and adapted to rest upon astememory contact 43.

is moved in one direction,it will connect stetionery contact 43 with another stationery plate 76 are two stationery contact When this switch-arm" cure of motor 10.

7 "2, and '73 are three electrr which ion 1 on clectrores ionsive purpose oi which is to eiitorne sistance out of the net 71 comprises :1 coil contact-plate 7G is co] lated from, the core inc I. 75. Above 78. Ei'iegnets 72 and 73 coinnrise similar parts.

I will now point out ti o y ricus electrical circuits shown. in this 131' and describe the operation oi this inve The mainline circuits and the niotoi'-eiiiist"-re circuits are designated by heavy lines, wlulc the opernting-ci'cuits and motor-field end generntor circuits are designated by light lines. Main-line conductor 31 con: ted to stetionery contacts 57 end in is reversing switch. I The nrnin-line COiHlU-t" 30 is connected'to stw onorycontacts id 6?inth reversing-switch. The ternnnels and 17 of shunt-field of motor 18 connected r spectively, to the main-line conductors and 31 by conductors 30 and 31". if an operator turns the handle 1 the manually-operated circuit-close the left, so that it closes the circuit he Ween stationery contacts 43 and it, a circuit will closed. thereby from main-line conductor-3O through conductor e32 circuit-closer 40, conductor 51 through inegnetwvinding' 5i, and to main-line conductor 31 through a conductor 51 The winding 51 will therefore be connected across the mains from the source of current-supply and will be energized thereby. It will then raise core 52 until contectp ates 53 and 54 are raised ageinst the contacts 57 Magnet 60 comand 58 and 55 and 56, respectively. A circuit 1 will be closed thereby from main line 30, C011", tacts 55 and 56, conductor 56*, resistance 7 O eraser short-circuits the remaining portion oi re- 65 sistance 70. The operation aboye described will be entirely automatic and the resistance to brush it, through motor-armature 11,0ut will be out out of the motor-armature circuit at brush 13, thenceby conductor 13 toconproportionately to the acceleration of the tacts 58 and '7, and thence to main-line conmotor-armaturefthat is, it will be cut out, ductor 31. As the field-winding oitemotor 1O is connected across the line and as the circuit is now completed through resistance 70' and armature 11 of motor 10, the motor-armature will begin to rotate in one direction. It may be seen that at the same time a circuit is closed through the motor-armature another circuit is closed from main line '30 through contacts 55 and 56, conductors 56 and 23 to terminal 23 of the enerator-field 2-1, through the generator-lied out at terminal 22, and through conductors 22 and 13 to contacts 58 and 57, and thence to mainline conductor 31. The'magnetic field of genorator will thus be quickly energized and the generator will begin to generate a voltage 2 which will be proportional in strength to the speedof the motor 10. The voltage thus generated is led through-conductors 26 and -27 to the windings oi the ma nets 71, 7 2,

and 73, which, as hown in t e drawing, are connected in arallel, and are thus connected across the rushes 24 and 25 of generator 20. As the speed of motor 10 increases, and consequently the current generated by generator 20 increases, these magnets 71, 72, and 73; will be energized thereby. The strength or. these magnets will therefore gradually increase as the speed of motor 10 increases The magnets may be arra'ngedto liit their cores step by step as the strength of this "current increases. This step-by-step effect may be obtained in various ways-as,

for example, by setting the cores at difierent positions Within the windings of the magnets, as is shown in the drawing. As the generated current increases the magnet 71 will reach a sufficient strength to attract and lift its core 75, when its contact-plate 7 6 will be brought up against stationary contacts 77 and 7 8. These stationary contacts are con-e nected by contacts 7 7*" and '78 to a portion of resistance 7 0. When contact-plate 76 is raised up against stationary contacts 77 and 78, the portion of resistance included be tween resistance 77 and 78 will be shortcircuited thereby. This in turn will allow more current to pass through the motor-armature and its speed will be accelerated thereby. The effect of this will be to increase the strength of current in magnets 71, 7 2 and 7 3, and as soon as the current strength reaches another predetermined amount mag.

net 72 will raise its core and contact-plate against another pair of stationary contacts,

peated until magnet 73 raises its core and quickly when the load upon motor 10 is light and its acceleration is rapid, or it will cut out more slowly when the load upon the motor 10 is heavier and its acceleration therefore is slower. When it is desired to stop the motor, the handle a1 0i manually-operated circuitcloserAO may be brought back to its central osition, when magnet 51 will be denergized and will allow its core and its connected con tact-plates to drop back away from the stationary contacts. The motor circuit will thus be broken, the motor will come to rest, and the movable parts of magnets 71, 72, and 7 3 will assume their initial position. if the operator had moved handle 41 to the right,- so that it closed a circuit upon stationary contacts 43 and 15, the operation'would have been similar; but in this case magnet would have been operated to close circuits between its stationary contacts and the current would have been supplied to the motorarmature 11 and to the generator'shunt-field 21 in the opposite direction. The motor would therefore rotate in the o posite direction. It may be seen that alt ough the armature of generator 20 will also rotate in the opposite direction its shunt-field 21 will have current s u plied to it in the opposite direction, so t at the current flowing from its brushes 24 and 25 will always be in the same direction regardless of its direction of rotation.

It is believed that this system .as described in combination with a starting device for electric motors has many advantageous uses and that it is applicable to many other electrical controllingdevices than that herein shown and described.

. What 1 claim is 1. An electric motor, a generator connect ed to run with the motor, a field for the generator, and a source of current-supply connected to the motor and to the field of the generator, and motor-controlling means separate from the field of the motor and operated by current from said generator.

2. An electric motor, a generator connected to run with the motor, a field for the generator, a source of current-supply, means for quickly exciting the generator-field when the current-supply is closed to the motor, and motor-controlling apparatus separate from ioo ITO

the field of the motor and operated by current from the generator 3. An electric motor a starting-switch therefor, a generator connected to run with the motor, a field for the generator, and a source of current supply connected to the 4. An electric motor, a reversing-switchtherefor, a generator connected to run With the motor, a field for the generator, a source of current-supply, contacts in said reversingsWitoh arranged to close a circuit to the motor and to the field of the generator, and

means connected to the generator but separate from the field of the motor, for controlling the acceleration of the motor.

5. An electric motor, an electrically-actuated reversing-switch therefor, a generator connected to run With the motor, a field for the generator, a source ofcurrent-supply, contacts in said reversing-switch arranged to close a circuit to the motor and to the field of the generator, said generator arranged to control the acceleration of the motor, anda manually-operated circuit-closer.

6. electric motor, having an armature and a field,

nected to'th'e motor-field, a reversing-switch whenever ed to run with the for the motor, a generator connected to run With the motor, a field for the generator, contacts in the reversing-switch to effect a rethe generatorfield connections the circuit through the motor-armature is reversed, and means operated by current fromthe generator to control the acceleration of the motor. I v 7. An electric motor, a generator connectmotor, a field for the gencurrent-supply connected versal of erator, a source of to the motor and to the field oi the generator,

an electroresponsive device arranged to control the accelerationof the motor, said electroresponsive device being actuated by the current of the generator.

8. An electric motor, a generator connected to run with the motor, a field for the generator, a source of current-supply connected the current of the generator:

b 9. ,An electric motor, a generator confiectment in they motif-circuit, a generator contor, an electroresponsive a source of current-supply con ranged to control the ated by thecurrent of the generator.

11. An electric motor having an armature and a field, an opposition element in the motor-armature circuit, a generator connected to run with the motor, afield for the generator, a source of current-supply conn'ected to the motor-field and to the field of the generadevice arranged to cut the opposition element out of the motorarmaturecircuit, said electroresponsive device being actuated step by step by the current of the generator.

12. An electric motor having an armature and'a field, a resistance in the motor-armature circuit, a with the motor, a field for the generator, a

motor-field and to the field oi -the generator, a plurality of electromagnets arranged'to cut the resistance out of the motor-armature circuit, said electromagnets being the current of the generator. 13. An electric motor, having an armature and a field, a resistance in the motor-armature circuit, a generator connected with the motor and proportional in strength'to the speed of the motor, a field for the generator, a source of current-supply connected to the motor-field and to'the field of the generator, a plurality of electromagnets-arranged to short-circuit the resistance in the armature circuit, said e the 'variable voltage of the generator.

14. electric motor having an armature and a fiel a resistance in the motor-armature circuit, an electrically-actuated reversingswitch for the motor, a generator connected with the motorand arranged to generate a voltage proportional in strength to the speed of the motor, a field for the generator, a source ofourrent-supply connected to the motor-field and to the field of the genera tor, a plurality of electromagnets arranged to electric motor, an opposition ele- I short-circuit the resistance in the armatureacceleration of the 1110-. tor, said electroresponsive device being actugenerator connected to run' source of current-supply connected to the actuated by l arranged to generate a voltage I I circuit, said eledtromagnets being actuated one by one by the variable voltage of the generator,and a manually-operated circuit-closer for the reversingswitch.

In testimony whereof I have signed my name to this specification in the presence of tWo subscribing Witnesses.

AXEL MAGKUSON. Witnesses:

JOSEPH 'E. CAVANAUGH, ERNEST W. MARsnALL, 

